Means for quantitative determination of analyte in liquids

Abstract

A testing module is provided having units which can be arranged seriatim to provide narrow through passageways linked to each other for quantitative determination of analytes passing through the units as by electrical testing with electrodes. Auxiliary passageways are preferably used in one unit to allow flushing of a first sample chamber without contamination from a second sample chamber. An electrode holder carries a membrane backed by a gel to aid in electrically linking the membrane to an electrode and to support the membrane in a substantially planar condition in use.

What is claimed is: 
     
       1. A testing module unit dimensioned and arranged to be used with at least one other module unit in an arrangement for testing an analyte in a liquid, said module unit having a body and a narrow diameter through passageway,   said passageway having an enlarged chamber intermediate ends of said passageway, said chamber being formed on one side by a membrane of an electrode,   said chamber lying substantially in a plane with a first portion of said passageway opening into an inlet of said chamber at an angle to said plane to cause turbulence substantially confined to said opening while permitting smooth flow beyond said opening whereby said chamber acts as a defuser at its entrance and as a nozzle at an exit thereof,   said chamber inlet having an opposed outlet with said chamber varying in cross section from said opening to exit,   said varying cross section being enlarged toward the center of the chamber and restricted at said exit in a predetermined shape to permit said chamber to act as a defuser and nozzle,   said passageway having a cross-sectional area corresponding to a diameter of from 0.015 inch to 0.05 inch,   said chamber having a maximum cross-sectional area less than ten times the cross-sectional area of said passageway,   said chamber defining an area greater than an area defined by said membrane whereby said membrane is wholly encompassed by said chamber,   said chamber comprising means for receiving an electrode holder in operative alignment therewith.   
     
     
       2. A testing module unit in accordance with claim 1 having an electrode holder operatively aligned therewith said electrode holder comprising an elongated electrode body having a source of electricity connected therethrough to an internal electrode lying within a first chamber therein,   said first chamber being elongated and open to a second chamber underlying a chemically sensitive ion testing membrane,   said first chamber being filled with an electrically conductive material and said second chamber being filled with a conductive gel whereby there is electrical continuity between said internal electrode and said testing membrane,   a soft resilient yieldable means for sealing said membrane,   said sealing means being adapted to be resiliently compressed to seal said membrane against a cuvette overlying said membrane whereby a sealed chamber can be defined in part by said membrane and said cuvette,   wherein said sealing means comprises a generally encircling mount for said membrane defining a planar surface to which said membrane is attached and maintained in substantially planar form.   
     
     
       3. A testing module unit in accordance with claim 2 wherein said electrode holder is resiliently mounted to said unit by a spring loaded removable means. 
     
     
       4. A testing module unit in accordance with claim 1 having an electrode holder operatively aligned therewith said electrode holder comprising an elongated electrode body having a source of electricity connected therethrough to an internal electrode lying within a first chamber therein,   said first chamber being elongated and open to a second chamber underlying a chemically sensitive ion testing membrane,   said first chamber being filled with an electrically conductive material and said second chamber being filled with a conductive gel whereby there is electrical continuity between said internal electrode and said testing membrane,   a soft resilient yieldable means for sealing said membrane,   said sealing means being adapted to be resiliently compressed to seal said membrane against a cuvette overlying said membrane whereby a sealed chamber can be defined in part by said membrane and said cuvette.   
     
     
       5. A testing module unit in accordance with claim 4 wherein said electrode holder is resiliently mounted to said unit by a spring loaded removable means. 
     
     
       6. An electrode holder for use in a testing module unit, said electrode holder comprising an elongated electrode body having a source of electricity connected therethrough to an internal electrode lying within the first chamber therein,   said first chamber being elongated and open to a second chamber underlying a chemically sensitive ion testing membrane,   said first and second chambers being filled with an electrically conductive material whereby there is electrical continuity between said internal electrode and said testing membrane,   a soft resilient yieldable means for sealing said membrane,   said sealing means being adapted to be resiliently compressed to seal said membrane against a cuvette overlying said membrane whereby a sealed chamber can be defined in part by said membrane and said cuvette.   
     
     
       7. An electrode holder in accordance with claim 6 and further comprising said sealing means comprising a generally encircling mount for said membrane defining a planar surface to which said membrane is attached and maintained in substantially planar form.